The invention relates to an amplifier arrangement for amplifying an audio signal.
Amplifiers are used for amplifying an audio input signal to give an amplified audio output signal, wherein the amplitude of the audio output signal is higher than the amplitude of the audio input signal. In addition to a multiplicity of analog amplifiers, so-called Class D amplifiers have become established on the market owing to the low number of component parts required and the high efficiency. In the case of Class D amplifiers, the incoming audio signal is converted into a pulse-width-modulated signal, which is then amplified by virtue of switching devices being opened and closed by the pulse-width-modulated signal. The resultant, amplified, pulse-width-modulated signal is converted into the amplified audio output signal using a low-pass filter.
The document DE 11 2006 003 184 T5, which is based on WO 2007/063490 and forms what is believed to be the closest prior art, discloses a full-bridge Class D power amplifier. The amplification part of the full-bridge power amplifier is implemented via two circuit branches, each having two controllable switches. The circuit branches each form a connection, via which a load, in particular a loudspeaker, can be connected. In each case one low-pass filter with a coil and a capacitor is arranged between the connection points and the load.